Characterization of hemicelluloses from Neolamarckia cadamba (Rubiaceae) during xylogenesis

Understanding the dynamic evolution of hemicellulose during Pinus taeda L. growth

Pinus taeda L. is a fast-growing softwood with significant commercial value. Understanding structural changes in hemicellulose during growth is essential to understanding the biosynthesis processes occurring in the cell walls of this tree. In this study, alkaline extraction is applied to isolate hemicellulose from Pinus taeda L. stem segments of different ages (1, 2, 3, and 4 years old). The results show that the extracted hemicellulose is mainly comprised of O-acetylgalactoglucomannan (GGM) and 4-O-methylglucuronoarabinoxylan (GAX), with the molecular weights and ratios (i.e., GGM:GAX) of GGM and GAX increasing alongside Pinus taeda L. age. Mature Pinus taeda L. hemicellulose is mainly composed of GGM, and the ratio of (mannose:glucose) in the GGM main chain gradually increases from 2.45 to 3.60 with growth, while the galactose substitution of GGM decreases gradually from 21.36% to 14.65%. The acetylation of GGM gradually increases from 0.33 to 0.45 with the acetyl groups mainly substituting into the O-3 position in the mannan. Furthermore, the contents of arabinose and glucuronic acid in GAX gradually decrease with growth. This study can provide useful information to the research in genetic breeding and high-value utilization of Pinus taeda L.

Integrated Hemicellulose Extraction and Papermaking Fiber Production from Agro-Waste Biomass

The present study deals with the valorization of corn stalks in an integrated processing strategy targeting two products: extracted hemicelluloses (HC) and papermaking fibers. Preliminary trials were conducted to assess the individual or the combined effects of biomass treatment on the quality of the obtained hemicelluloses and papermaking fibers. Depending on the hot alkaline extraction (HAE) conditions, the extracted HC had a xylan content between 44-63%. The xylan removal yield ranged between 19-35%. The recovery of HC from the extraction liquor and final black liquor was significantly affected by process conditions. The experimental approach continued with the study of HAE conditions on the obtained paper's mechanical properties. The optimization approach considered conserving paper strength properties while achieving an equilibrium with the highest possible HC extraction yield. The optimal values are sodium hydroxide concentration (1%), process time (33 min), and temperature (100 °C). The xylan content in the separated HC sample was ~55%. An extended extraction of HC from the resulting pulp under hot alkaline conditions with 5% NaOH was performed to prove the HC influence on paper strength. The xylan content in HC samples was 65%. The consequence of xylan content reduction in pulp leads to 30-50% mechanical strength loss.

Effects of salicylic acid-grafted bamboo hemicellulose on gray mold control in blueberry fruit: The phenylpropanoid pathway and peel microbial community composition

Bamboo hemicellulose (HC) is a natural plant polysaccharide with good biocompatibility and biodegradability. But its poor antibacterial activity limits its application in fruits preservation. In this study, based on the good inducer of salicylic acid (SA) for plant diseases resistance, a novel antibacterial coating material was synthesized by grafting SA onto HC. The study aimed to investigate the synergistic effect of HC-g-SA on antibacterial ability, induces diseases resistance and microbial community composition of postharvest fruit. The graft copolymer treatment significantly reduced the incidence of gray mold caused by Botrytis cinerea in blueberries during storage (P < 0.05), and significantly stimulated the activity of key enzymes, including phenylalanine ammonia-lyase, chalcone isomerase, laccase, and polyphenol oxidase, leading to an increase in fungicidal compounds such as flavonoids, lignin, and total phenolics produced by the phenylpropanoid pathway in blueberries (P < 0.05). Moreover, the HC-g-SA coating altered bacterial and fungal community composition such that the abundance of postharvest fruit-peel pathogens was significantly reduced. After 8 days storage, the blueberry fruits treated by HC-g-SA had a weight loss rate of 12.42 ± 0.85 %. Therefore, the HC-g-SA graft copolymer had a positive impact on the control of gray mold in blueberry fruit during postharvest storage.

Catalytic and antioxidant activity of silver nanoparticles fabricated by Neolamarckia cadamba bark extract

Plant parts have unfathomable potential in the synthesis of nanoparticles. The current study was designed for the photosynthesis of silver nanoparticles (NC-AgNPs) using bark extract of N. cadamba. Different analytical methods were used to characterize the synthesized nanoparticles. HR-TEM analysis identifies the formation of multi-shaped NC-AgNPs like spherical, quasi-spherical, rod-shaped, trigonal, square, pentagonal, and hexagonal with a size range of 18-91 nm. The crystallize size of NC-AgNPs was found to be 27.6 nm. The catalytic effectiveness of NC-AgNPs in degrading Crystal violet (CV) dye is remarkable. Important parameters such as the effect of catalyst dose and pH were investigated. Dose-dependentantioxidant activity of NC-AgNPs was determined by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. Low-cost synthesis and eco-friendly reagents were the salient features that made NC-AgNPs more attractive toward catalytic and antioxidant activities.

Effect of Loblolly Pine (Pinus taeda L.) Hemicellulose Structure on the Properties of Hemicellulose-Polyvinyl Alcohol Composite Film

Hemicellulose is the second most abundant natural polysaccharide and a promising feedstock for biomaterial synthesis. In the present study, the hemicellulose of loblolly pine was obtained by the alkali extraction-graded ethanol precipitation technique, and the hemicellulose-polyvinyl alcohol (hemicellulose-PVA) composite film was prepared by film casting from water. Results showed that hemicellulose with a low degree of substitution is prone to self-aggregation during film formation, while hemicellulose with high branching has better compatibility with PVA and is easier to form a homogeneous composite film. In addition, the higher molecular weight of hemicellulose facilitates the preparation of hemicellulose-PVA composite film with better mechanical properties. More residual lignin in hemicellulose results in the better UV shielding ability of the composite film. This study provides essential support for the efficient and rational utilization of hemicellulose.

The comprehensive characterization of Prosopis juliflora pods as a potential bioenergy feedstock

The production of renewable and sustainable biofuels using inevitable wastes is a promising alternative to the alarming depletion of fossil fuels. Significantly, the sustainable biorefinery of lignocellulosic waste, as an alternative fuel source, is a prognosticating approach to tackle many agricultural/forestry residues and offers a circular economy as well as environmental benefits. But, the heterogeneity of lignocellulosic biomass is one of the major bottlenecks in lignocellulosic biorefinery. Thus the characterization of lignocellulosic biomass is essential to understanding the feedstock's nature, composition and suitability for biofuel production. The present study taps evergreen spiny non-edible pods of Prosopis juliflora (Pj) as an energy feedstock. Proximate, ultimate and biochemical characterization of Pj pods were conducted, and thermal behaviour and calorific values were determined. Cellulose and hemicellulose were isolated and characterized by reliable methods. The overall characterization has revealed the Pj pods as a potential feedstock for bioenergy. The collected Pj pods contain (% w/w) moisture 7.89 ± 0.002, volatile matter 87.67 ± 0.002, ash 0.21 ± 0.002, fixed carbon 4.23 ± 0.002 with a calorific value of 17.62 kg/MJ. The CHNS content was (w/w %) carbon 41.77, nitrogen 3.58, sulfur 26.3 and hydrogen 6.55. The biochemical composition analysis yields (% w/w) on a dry basis; cellulose 26.6 ± 0.18, hemicellulose 30.86 ± 0.27, lignin 4.71 ± 0.12, protein 11.63 ± 0.12 and starch 1.1 ± 0.06 and extractives 30.56 ± 0.008. The isolated cellulose and hemicellulose were analyzed and confirmed by CP/MAS &¹H NMR, FTIR, TG-DSC, SEM, XRD, and TGA. The present results revealed that the tested biomass, Prosopis juliflora, could be used as a feedstock in biorefinery for bioenergy.

The physiological and transcriptomic study of secondary growth in Neolamarckia cadamba stimulated by the ethylene precursor ACC

Though many biological roles of ethylene have been investigated intensively, the molecular mechanism of ethylene's action in woody plants remains unclear. In this study, we investigated the effects of exogenous 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, on the growth of Neolamarckia cadamba seedlings, a fast-growing tropical tree. After 14 days of ACC treatment, the plants showed a reduced physiological morphology while stem diameter increased; however, this did not occur after the addition of 1-MCP. Meanwhile, the lignin content of N. cadamba also increased. Transcriptome analysis revealed that the expression of the ethylene biosynthesis and signaling genes ACC oxidase (ACO) and ethylene insensitive 3 (EIN3) were up-regulated mainly at the 6th hour and the 3rd day of the ACC treatment, respectively. The transcription levels of transcription factors, mainly in the basic helix-loop-helix (bHLH), ethylene response factor (ERF), WRKY and v-myb avian myeloblastosis viral oncogene homolog (MYB) families, involved in the ethylene signaling and secondary growth also increased significantly. Furthermore, in accordance to the increased lignification of the stem, the transcriptional level of key enzymes in the phenylalanine pathway were elevated after the ACC treatment. Our results revealed the physiological and molecular mechanisms underlying the secondary growth stimulated by exogenous ACC treatment on N. cadamba seedlings.

Physiological and Transcriptomic Responses of Growth in Neolamarckia cadamba Stimulated by Exogenous Gibberellins

(1) The phytohormones gibberellins (GAs) play a crucial role in plant growth and development, such as seed germination, flowering, fruiting, and stem elongation. Although many biological roles of GAs have been studied intensively, the molecular mechanisms of GAs in woody plants are still unclear. (2) In this study, we investigated the effects of exogenous application of GAs on Neolamarckia cadamba. (3) The height and biomass of N. cadamba increased after 7 days of GA treatment, especially on the second internode. Transcriptome analysis showed that although the majority of genes involved in the GA signaling pathway were up-regulated, the expression of GA20 oxidase (GA20ox) and GA3 oxidase (GA3ox) was down-regulated in the 3 days GA-treated group compared to the CK group. The expression of the cell elongation-related basic helix-loop-helix genes bHLH74 and bHLH49 was up-regulated in the GA-treated group compared with the CK group. Transcriptional expression levels of transcription factors involved in hormone signaling were changed, mainly including bHLH, ethylene response factor (ERF), and WRKY families. In addition, the transcriptional expression level of the key enzymes engaged in the phenylalanine pathway was downregulated after GA treatment. (4) In brief, our findings reveal the physiological and molecular mechanisms of exogenous GA treatment stimulation in N. cadamba.

Steam explosion of Aucoumea klaineana sapwood: Membrane separation of acetylated hemicelluloses

The fractionation of the aqueous effluent of Aucoumea klaineana Pierre (Okoumé) sapwood steam explosion was examined by a sequential-dilution type membrane diafiltration. The permeate and retentate fractions were characterized by HPLC-SEC, HSQC-NMR, FTIR, UV-visible and HPAE-PAD ion chromatography. Diafiltration with 10 kDa regenerated cellulose membrane has been shown to provide efficient fractionation without fouling. O2 and/or O3 acetylated xylans with a lower proportion of O2 and/or O3 acetylated glucomannans were isolated in the retentate (≈35% w/w and 1.08 w/w% based on initial effluent solid content and on initial dry wood respectively, including 65% w/w in the range 9-22 kDa). The molecular weights of the polysaccharides were significantly higher than those obtained by ethanolic precipitation. The permeate concentrated low molecular mass oligomers (90% w/w < 2.3 kDa, 1.88 w/w% based on initial dry wood) composed of pectic sugars, highly acetylated xylans (DS ≈ 0.9) and relatively high proportion of soluble lignin (≈40% w/w) including Lignin-Carbohydrate Complexes (LCCs).

Potassium deficiency inhibits leaf growth and promotes leaf necrotic spots in Neolamarckia cadamba (Roxb.) Bosser

Leaves, being a key plant organ involved in photosynthesis, play an important role in plant growth and development. Although there have been a few studies on the effects of potassium (K+) deficiency on the leaves of woody plants, knowledge about mechanism of necrotic spot formation on leaves during K+ deficiency is scarce. We used a hydroponics setup to understand the effects of K+ deficiency on Neolamarckia cadamba (Roxb.) Bosser. K+ deficiency resulted in smaller leaves and necrotic spots on the older leaves, whereas regulatory modules of the differentially expressed genes (DEGs) involved in cell proliferation, cell cycle and cell expansion were downregulated. K+ deficiency increased the activity of reactive oxygen species scavenging enzymes such as superoxide dismutase, ascorbate peroxidases and malondialdehyde, and expression of DEGs related to these was also upregulated. Strong diaminobenzidine staining was observed on the older leaves showing accumulation of H2O2 during K+ deficiency treatment. In addition, putrescine and ethylene synthesis genes were upregulated. Fifteen DEGs in response to ethylene signaling, including ETR1, ETR2, EBF1, ERF1 and ERF2, were upregulated in the third week. The leaf growth changes caused by K+ deficiency in N. cadamba were well demonstrated by our findings.

Characterization of hemicellulose during xylogenesis in rare tree species Castanopsis hystrix

Hemicellulose is an important component of the plant cell wall which vary in structure and composition between plant species. The research of hemicellulose structures is primarily focused on fast-growing plants during xylogenesis, with slow-growing and rare trees receiving the least attention. Here, hemicellulose structure of the rare species Castanopsis hystrix during xylogenesis was analyzed. Acetyl methyl glucuronide xylan was the most common type of hemicellulose in C. hystrix, with a unique tetrasaccharide structure at the reducing end. Hemicellulose type, structure, molecular weight, thermal stability, biosynthesis and acetyl substitution content and pattern remained stable during the xylogenesis in C. hystrix, which could be attributed to its slow growth. The stable polymer type, low side chain modification and high acetyl substitution of hemicellulose throughout the stems are among the reasons for the hardness and corrosion resistance properties of C. hystrix wood. Genetic modification can be used to improve these properties.

Isolation and structure characterization of glucuronoxylans from Dolichos lablab L. hull

Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC-MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-β-Xylp-(1→ backbone with substitution at O-2 site by α-GlcpA/4-O-methyl-α-GlcpA. The molar ratio of β-Xylp to α-GlcpA was 6.9:1, and acetylation was mainly at O-3 site of β-Xylp with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight (M_w). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of β-Xylp to α-GlcpA of 5.6:1. Besides, DLHP-1 (M_w of 20.0 × 10³ g mol^-1) adopted semi-flexible chain, while DLHAP-1 (M_w of 15.4 × 10³ g mol^-1) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab.

Characterization of hemicellulose in Cassava (Manihot esculenta Crantz) stem during xylogenesis

Cassava is one of the three major potato crops due to the high starch content in its tubers. Unlike most current studies on the utilization of cassava tubers, our research is mainly focused on the stem of cassava plant. Through nuclear magnetic resonance (NMR), fourier transform infrared spectrometer (FTIR) and other methods, we found that cassava stalk hemicellulose consists of β-1,4 glycosidic bond-linked xylan backbone with a tetrasaccharide reducing end and decorated with methylated glucuronic acid, acetyl groups and a high degree of arabinose substitutions. Hemicellulose content gradually increased from the upper to the lower parts of the stem. The apical part of cassava stalk contained more branched and heterogeneous glycans than the middle and basal parts, and the molecular weight of hemicellulose increased from top to bottom. Our findings will be helpful in understanding of structural variations of cassava hemicellulose during xylogenesis, as well as in better utilization of cassava plant waste in industry.

Physiological and Transcriptomic Responses to Nitrogen Deficiency in Neolamarckia cadamba

Nitrogen (N) is one of the abundant and essential elements for plant growth and development, and N deficiency (ND) affects plants at both physiological and transcriptomic levels. Neolamarckia cadamba is a fast-growing woody plant from the Rubiaceae family. However, the physiological and molecular impacts of ND on this species have not been well investigated. Here, we studied how N. cadamba responds to ND under hydroponic conditions. In a physiological aspect, ND led to a reduction in biomass, chlorophyll content, and photosynthetic capacity. ND also impaired the assimilation of N as the activities of glutamine synthetase (GS) and nitrate reductase (NR) were decreased in the root. Interestingly, the lignin content of stem increased progressively during the ND stress. The main transcription factors, the transcription factors that are important to N regulation has been found to be upregulated, including Nodule inception-like protein 7 (NLP7), TGACG motif-binding factor 1 (TGA1), basic helix-loop-helix protein 45 (BHLH45), NAM, ATAF1,2, CUC2 (NAC) transcription factor 43 (NAC43), and basic leucine zipper pattern 44 (bZIP44). The expression of N transporters, such as nitrate transporter 2.4 (NRT2.4), ammonium transporter 3 (AMT3), and amino acid transporter protein 3 (AAP3), was also upregulated. In addition, phosphorus- and calcium-related genes such as phosphate starvation response 2 (PHR2) and cyclic nucleotide-gated ion channel 15 (CNGC15) were expressed more abundantly in response to ND stress. Our results reveal the physiological and molecular mechanisms by which woody plants respond to ND.

Efficient and Selective Catalytic Conversion of Hemicellulose in Rice Straw by Metal Catalyst under Mild Conditions

Rice straw is an abundant material with the potential to be converted into a sustainable energy resource. Transition-metal catalysis activated the C–O bond in the hemicellulose of raw rice straw, cleaving it to form monosaccharides. The mechanism of rice straw catalytic conversion had a synergistic effect due to in situ acid catalysis and metal catalysis. The conditions for the hydrogenation of hemicellulose from rice straw were optimized: catalyst to rice straw solid/solid ratio of 3:10, stirring speed of 600 r/min, temperature of 160 °C, time of 3 h, solid/liquid ratio of 1:15, and H2 gas pressure of 1.5 MPa. An excellent hemicellulose conversion of 97.3% with the yields of xylose and arabinose at 53.0% and 17.3%, respectively, were obtained. The results from FTIR and SEM experiments also confirmed the destruction of the rigidity and reticulate structure of rice straw after the catalytic reaction.

Prevention of loperamide induced constipation in mice by KGM and the mechanisms of different gastrointestinal tract microbiota regulation

Constipation is one of the most prevalent gastrointestinal tract diseases. Konjac glucomannan (KGM) dietotherapy can effectively relieve the clinical symptoms of patients with constipation. However, the causal relationship among KGM, constipation and different gastrointestinal microbiome (i.e., the stomach {St}, small intestine {S}, and large intestine {L}) remains poorly understood. In this study, constipated mice were treated with KGM (75, 150, 300 mg/kg bw). Results showed that KGM treatment improved the general physiological state, fecal character, small intestinal propulsive rate, gastric emptying rate, MTL and AchE activities, ET-1, 5-HT, and NO levels, and SCFA concentrations. KGM in the diets of constipated mice reduced the diversity of St and S microbiota, while increased those in the L. The KGM intervention regulated the microbiota profile, which afterwards was closer to the normal mouse group: confirmation was provided by different changes of bacteria like Lactobacillus, Bifidobacterium and Allobaculum spp et al.

Preparation and antioxidant activities of polysaccharides obtained from abalone viscera by combination of enzymolysis and multiple separation methods

Abalone viscera were byproducts of the abalone processing and usually discarded as wastes. In this study, we tried to obtain functional polysaccharides from abalone viscera by a combination of enzymatic hydrolysis, membrane separation, anion exchange chromatography, and gel filtration techniques. Abalone viscera underwent successive hydrolyzation with alcalase and flavourzyme. Each enzymolysis was followed by deproteinization via membrane separation. The final yield of crude abalone viscera polysaccharide (CAVP) was 19.72%; the polysaccharide content of CAVP was 51.75%. Furthermore, three fractions of polysaccharides (AVP1, AVP2, and AVP3) were isolated from the CAVP by anion exchange chromatography and gel filtration. The molecular weights of each AVP were 14.99 kDa, 58.48 kDa, and 39.63 kDa, with a carbohydrate content of 62.75, 23.09, and 44.67%, respectively. These AVPs showed excellent antioxidant activities in vitro. Our results provide a scientific basis for the further utilization of polysaccharides from abalone viscera. PRACTICAL APPLICATION: This study demonstrated an eco-friendly approach for industrial production of high purity animal-derived polysaccharides without any environmental pollution caused by the viscera waste of abalone and promoting the comprehensive utilization of abalone resources.

Characterization of hemicelluloses in sugarcane (Saccharum spp. hybrids) culm during xylogenesis

Hemicelluloses are effective renewable biopolymers that can be used in many different industrial processes and preparations. In plants, the content of hemicellulose might change with different developmental stages and/or tissues. Thus, in here chemical and structural differences in hemicellulose isolated from the apical, middle and basal segments of sugarcane stem were characterized using chemical techniques. Further, difference in expression levels of genes related to synthesis of hemicelluloses from these three segments were studied by RNA-seq and qRT-PCR etc. The sugarcane hemicellulose backbone was xylose residues connected via β-1,4 glycosidic linkages which was further substituted with arabinose, acetyl and glucuronic acid side chains. Hemicellulose content was higher in the middle and basal segments with less backbone substitutions compared to apical segments. In terms of gene expression, hemicellulose synthesis and modification genes were intensely expressed in middle and basal segments. Taken together, our research describes differences in hemicellulose content and substitutions in sugarcane during xylogenesis, which will increase our knowledge for finding more refined use of sugarcane bagasse.

Acacia Xylan as a Substitute for Commercially Available Xylan and Its Application in the Production of Xylooligosaccharides

Over the past two decades, birchwood and beechwood xylans have been used as a popular substrate for the characterization of xylanases. Recently, major companies have discontinued their commercial production. Therefore, there is a need to find an alternative to these substrates. Xylan extraction from Acacia sawdust resulted in 23.5% (w/w) yield. The extracted xylan is composed of xylose and glucuronic acid residues in a molar ratio of 6:1 with a molecular mass of ∼70 kDa. The specific optical rotation analysis of extracted xylan displayed that it is composed of the d-form of xylose and glucuronic acid monomeric sugars. The nuclear magnetic resonance analysis of extracted xylan revealed that the xylan backbone is substituted with 4-O-methyl glucuronic acid at the O2 position. Fourier transform infrared analysis confirmed the absence of lignin contamination in the extracted xylan. Xylanase from Clostridium thermocellum displayed the enzyme activity of 1761 U/mg against extracted xylan, and the corresponding activity against beechwood xylan was 1556 U/mg, which confirmed that the extracted xylan could be used as an alternative substrate for the characterization of xylanases.

Anionic structural effect on the dissolution of arabinoxylan-rich hemicellulose in 1-butyl-3-methylimidazolium carboxylate-based ionic liquids

The exploration of a highly efficient and environment-friendly solvent for dissolving hemicellulose is significant. In this study, 1-butyl-3-methylimidazolium carboxylate ([Bmim]carboxylate)-based ionic liquids (ILs), including [Bmim]formate, [Bmim]acetate, [Bmim]propionate, and [Bmim]butyrate, were used as solvents to dissolve arabinoxylan-rich hemicellulose from bamboo. The hemicellulose solubility in the ILs was determined as a function of temperature. The interaction between the hemicellulose and the ILs was evaluated by using ¹H and ¹³C NMR techniques. The hemicelluloses regenerated from the saturated IL solutions were characterized. Results showed that the temperature and structure of carboxylate anions deeply affected the hemicellulose solubility. The carboxylate anion played a more important role than the imidazolium cation in hemicellulose dissolution. The hydrogen bond that formed between the ILs and the hydroxyl groups at the XC2 position of xylopyranose units of hemicellulose was stronger than that between the ILs and the hydroxyl groups at XC3 position of xylopyranose units. The hydrogen bond strength between the hemicellulose and the ILs was affected by the alkyl chain of the carboxylate anion and the hemicellulose concentration. The disruption of the inter- and intra-molecular hydrogen bonds in hemicellulose by the ILs was responsible for the hemicellulose dissolution. The main chain of hemicellulose remained nearly unchanged during the dissolution process.

The exploration of a highly efficient and environment-friendly solvent for dissolving hemicellulose is significant.

Characterization of Lignin Structures in Phyllostachys edulis (Moso Bamboo) at Different Ages

Bamboo is a gramineous plant widely distributed in China and has great prospects. Normally, local people cut bamboo culm at first year for paper milling or at six years for construction. Understanding lignin changes in bamboo with aging is necessary for better exploring the application of bamboo at different ages and can also promote the application of bamboo more effectively. Based on the previous study, the chemical structure and the lignin content of bamboo at different ages were further explored by FT-IR, GPC, NMR and other chemical methods in this paper. Results showed that the lignin structures of bamboo at different ages were similar with three monomers of S, G and H, but the molecular weight increased with age. Quantitative structure estimation further confirmed that S-type lignin content and S/G ratio of bamboo lignin constantly increased with age.